Tracklaying tractor



C. L. BEST TRACKLAYING TRACTOR Jani. 24, 192s. '1,656,899

Filed March 24, 1923 2 sneaks-sheet l i \U) l l KU) l l KU) I l 0 O 3mm m, w28. msgg C. L. BEST TRACKLAYING TRACTOR Filed March 24, 1923 2 Sheets-Sheet' 2 Patented dan, 24, W2,

U IT E D P F F l C E ULARENGE LE() EEST, 0.7i? Stahl LEANDRO, CALIFORNIA, SSIGNOR, BY MESNE ASSIGN-I MlENTS, TO CATERPILlLz-"LR TRACTOR C0.,

PORTIUN F CALIFORNIA.

F SAN LEANDRQ, CALIFORNIA, A COR- TRACKLAYING TRATOR.

nppneaunnried March a4, 192s. serial no. 627,278.

This invention relates to improvements in track laying tractors, and more especially to an improved safety device and idler adjustment therefor, l

In the operation of track laying tract'ors over sandy soil, gravel or sticky mud, the sprocket wheels `often become plugged with dirt. The accumulation in the bottom of the sprockets becomes so hard packed or caked andl built up that tremendous tension. is put on the tracks, tracks from the wheels and the bending up oi the heavy truck frame channels resu tine in serious damage, putting the machine out l5 of operative condition, and requiring considerable time and work for repairs.

The object of the present invention is to provide improved means of a Simple eicient nature that while serving to hold the t0 front idler bearing rmly xed in its adjusted position under normal conditions, will yield or give way when the track 1 3 subject to undue strain, permitting the idler wheel bearing to move back and relieve the parts-of strain without serious damage, and providing for the 'quick readjustment of the parts to working position.

The invention, with other objectsand advantages thereof, and the particular conau struction, combination and arrangement of parts comprising the. same, will be understood from the hereinafter contained detail description, when considered in connection with the accompanying drawings, forming part hereof, and illustrating one embodiment of the invention.

In the drawings:

Figure l is aside elevation of a tractor truck equipped with safety adjusting and holding means in accordance with the present invention.

Fig. 2 is a detail sid-e elevation of the safety adjusting and holding means for the idler bearing. f

Fig. 3 is a detail plan of the safety idler ad'usting andrholding means.

ig. 4 is a detail viewof one of the yieldable members of the safety adjusting and holding means. The invention comprehends means for adjusting and holding the bearing of the front wheel or idler surface of the tractor truck causing disengagement of the` includinga rod member adapted to be interposed between a part on the truck frame and the idler bearing, and adaptedto yield when the tread is subjected to excessive f strain. More particularly the invention contemplates a rod or piece of metal adapted to be interposed between and detachably intert at its ends with one end of an adjusting screw and with the idler bearing, and adapted under undue pressure to buckle or bend and permit the idler bearingto move relatively to the frame and relieveA the parts of strain. l

. While in the drawings is illustrated a referred embodimentof the invention, w ich has proven satisfactory in practice, it will of course be understood that minor changes and variations in the particular constructlon shown, and the, embodiment of the invention in other forms, as will appeal to those skilled inthe art and falling within the scope of the appended claims, may be practiced without departing from the spir1t of the invention. 4

In .the drawings, the invention is shown applied to one of the well known forms of tractor trucks the same comprising spaced parallel channels a, and endless treads b, a rear driving spocket c and a front idler surface or wheel d, the latter having an axle d mounted in bearings als on the channels a. e, f, desi ate respectively sets of bolts and plates o conventional form for clamping the idler bearing d3 tothe truck frame channels a.

The particular embodiment of my improved safety idler adjusting and holding means illustrated in the drawings, comprises a horizontally extending adjusting screw g having a threaded engagement with a fixed .upstanding part or bracket h on one of the channels a, and ya yieldable member in the form'o a metal rod or piece z' adapted to be interposed between and have a detachable interfitting engagement at its ends with. one end of the adjusting screw g and the idler bearing idler 4bearing da being shown provided respectively with seats or depressions g', d* for the end portions of the metalv rod or iece As shown there are a pair of such a justda, the adjusting screw g and the ing screw and yieldable rod being associated with each of the channels a and one end portion of the idler'bearing al? at either side lof the idler al.

may be constructed of any suitable material.

In the construction shown, the yieldable' members 'i are constructed of three quarter inch cold rolled steel, and said members or rods have tapering end portions e", the depressions screw g and the idler bearingleZB-"alsobeing correspondingly tapered as shown.

In the use of m improved safety -idler i" adustment and hol ing means rthe yieldable ro s or pieces are engaged with the adjusting screws and the idler bearing, land the adjusting screws are then turned upto properly adjust the idler bearing and tighten the* tread, the sets of clamp bolts e being then tightened to clamp the idler bearing to, the channels a and as will beunderstood the track can e tightened, from time to time as desired through the adj sting" screws. Under normal operative conditions the idler bearing will be held in adjusted position by the .clamp bolts and plates e, f, and the adusting screws g` and the rods or pieces z' ut should the tread b be subjected to excessive strain, the rods or pieces i will bend or buckle and permit the idler bearing to move back and relieve the parts of strain. When this occurs, after the caked dirt has been chiseled out or freed from the sprockets of the wheels, the' bent'rods or pieces" 'i are removed, straightened, and used over again, or new ieces may be substituted therefor.l the truc mechanism being quickly readjusted.

It will struction and arrangement of before set forth, means of a simple efficient nature is afforded for adjusting and holding the idler bearing in position under normal operative conditions, and which at the same be noted that by the special conparts hereinmembers, rods or pieces or seats -g-al-*- of the adjusting.n

time functions as a safety device or protector for the mechanism whereby bending up of the truck frame channels when the sprockets become caked with dirt and expensive re'pairs and loss of time incident thereto, are entirely avoided.

What I claim is:

1; In 'a track laying tractor, a truck frame, an endless tread, a driving sprocket and an idler Jfor the tread, a journal bearing on the frame for the idler, and means for holding the said idler bearing in place on the frame, said means including a part on the frame, and a rigid member engaging said frame part and the idler bearing, said member being of predetermined strength to hold the idler bearing in fixed position under normal operating conditions and, adapted to yield under excessive strain.

2. In a track-laying tractor, a truck frame, an endless tread, a driving `sprocket and an idler for" the tread, a journa bearing on the frame for'A the idl'efand means for said idler bearing in place on the trame, said means including a part on the trame, an

adjusting screw having an adjustable thread* edengagem'ent with said frame part, and a rod interposed between and having its opposite end portions interlitting `with one end of saidradjustingl screw and with a portion of the idler bearing, said rod beinfr'of predetermined strength to hold the idler bearing in fixed position under normal operating conditions and adapted to yield under excessive strain.

3. In a track laying tractor, a truck Jframe, an endless tread, a driving sprocket and an idler for the tread, a journal bearing on the frame for the idler, and means for holding the idler. bearing in place on the frame, said means including a part on the frame, an adjusting screw having an adjustable threaded engagement with said frame part, and a rod interposed between the adjusting screw and 'the journal bearing saidrod being of predetermined strength to hold the'idler bearing in fixed position under normal operating conditions and adapted to yield under excessive strain, said adjusting screw at one end and theidler bearing'eaclibeing provided with a socket adapted to receive one end portion of the rod.

In testimony whereof I hereunto affix my signature.

CLARENCE LEO BEST.'

holding 

